1. Field
The present disclosure relates generally to battery devices, and more particularly for a boost converter topology for high efficiency and low battery voltage support.
2. Background
Wireless devices and smart phones are increasingly used for a wide variety of tasks such as making and receiving calls, accessing and sending email, retrieving data, as well as entertainment. These enhanced features often require significant amounts of battery power. Often these phones have improved touchscreen displays for better viewing experiences.
Future generation batteries are progressing towards a technology (such as silicon anode) which can retain significant usable charge down to 2.5 volts. At low input voltages (Vin), conventional boost operation becomes significantly less efficient, and with some topologies boost operation is unable to deliver the desired current without going to significantly high coil inductance and/or switching technologies.
Silicon anode technology for new batteries uses high performance lithium ion batteries. Silicon anodes have the highest known theoretical charge capacity, much more charge capacity than current conventional anodes.
In addition, driving the need for efficient boost operation is the increasing use of high density displays. These high density displays provide an increased used experience and better viewing, which is especially useful for some applications. The dominant market segment of these displays use a matrix configuration of White Light Emitting Diode (WLED) to backlight the display. As the display density increases, there is a direct correlation to the increase in the number of WLEDs used for the backlight and consequently an increase in the backlight power consumption. Since a WLED typically has an operating voltage of 3V, several of these WLEDs are stacked in a series configuration and this requires the battery voltage to be boosted up to power the WLED stack. With an increasing number of WLEDs in the display the power consumption of the boost converter power operation becomes a significant portion of the total system power. Run time efficiency and the ability to boost efficiently from very low battery voltages needs to be improved to make better use of the capabilities of the newer generation of batteries.
There is a need in the art for improvement in total run time by increasing the efficiency of the WLED boost converters, particularly when used with silicon anode batteries.